Compostable means they degrade only in large piles of debris such as municipal waste centres, which get hot enough to break down the bag. The plastic is broken down, but it remains in the soil.

Paper bags are not a good replacement. Reusable shopping bags are the only environmentally sound replacement for the plastic bags, the so-called “biodegradable” plastic bags and the compostable plastic bags.

How much trouble is it to carry a lightweight reusable bag? No trouble at all when you consider that you might be saving the lives of marine life and you will help protect our endangered environment.